1. Field of the Invention
The present invention relates generally to a musical instrument; and more specifically, to a support structure for a string instrument.
2. Description of Related Art
String instruments are centuries old. Such instruments typically use a sound box, fretted neck and strings stretched taunt across or over the sound box whereby strumming or plucking the strings causes them to vibrate and create a sound. Depressing a string against the fretted neck changes the effective length of the string, which in turn changes the frequency at which the string vibrates when plucked. One type of such a string instrument is a guitar. Today's guitars create sound either mechanically or electronically, forming two categories of guitar; acoustic, using mechanical amplification or electric, using electronic amplification.
With an acoustic guitar, plucking the strings causes vibration of a soundboard. The soundboard produces sound by resonance; specifically, the soundboard transmits the vibrations of the strings to the air. In addition, the body of the guitar forms a resonating chamber that further shapes and projects the sound. With electric guitars, transducers, known as pickups, convert string vibration to an electronic signal wherein the electronic signal is routed to an amplifier and then to a speaker.
One drawback of an electric guitar constructed with a hollow body is that uncontrolled resonance issues often result in feedback when the amplified sound waves from the speaker induce intensified resonant vibrations in the top plate or body of the guitar consequently increasing the amplitude of the original string vibration, typically at one or more of the resonant harmonic frequencies of the guitar body. Accordingly, in an attempt to control feedback problems occurring in an electric hollow body guitar, various guitar body structures were developed including solid-body guitars.
Although tending to be very resistant to feedback, one drawback of a solid-body electric guitar is that the characteristics of the sound produced generally lacks the resonant complexity of a hollow-body guitar. An advantage of a solid-body guitar is that a vibrating string can be allowed to sustain its vibration for a longer period of time since less of the string vibration energy is transferred into creating resonant vibration of the guitar body.
While typically having a solid body to prevent feedback problems, electric guitars may also have a semi-hollow guitar body. One advantage of a semi-hollow guitar body is the capability to produce complex resonant tones more characteristic of hollow-body guitars while still limiting susceptibility to feedback. One early historically significant example of a semi-hollow guitar is the Gibson ES-335 introduced in 1958 that featured a wooden block positioned in the center of the body and glued to both the top and bottom plates; see FIG. 8. For other more recent innovations see for example Baker, U.S. Pat. No. 6,459,024 disclosing a torsion brace connected to the body at three locations, the head portion, the heel portion and bridge support portion. In addition, Minakuchi, U.S. Pat. No. 6.646,189 discloses an electric guitar having a body having a center block extending from the head to the heel with a pair of side bridges extending from the center block to the frame.
Accordingly, the prior art discloses various body structures designed to control body structure vibration and correspondingly feedback occurring during amplified guitar use while still providing some measure of resonance. What is needed is a guitar body structure that better optimizes resonant characteristics, provides improved capability to sustain notes, and minimizes susceptibility to feedback while achieving a distinct guitar sound.